Various packaging methods have been used for protecting, for example electronic components, during storage and transit. These methods, in addition to being generally labor-intensive, commonly involve a substantial outlay in cost and material-resources on packaging items in the form, for example, of cardboard cases and specially-designed items of plastics foam and corrugated cardboard to fit within them.
A form of packaging case that may be used with advantage environmentally and economically is described in GB-A-2414728. The rectangular packaging case described is of a thermoformed plastics-sheet construction having four walls that are hinged together to fold from flat in erection of the case round the article or articles to be protected. The walls have flanges at each end of the case that come into edge-to-edge abutment with one another in the erected case. The abutting edges of the flanges are each formed with ridges and grooves that run side-by-side with one another along the respective edge, and these ridges and grooves nest ridge-within-groove with the edge or edges of the other flanges abutted in the erected case. This mutual ridge-within-groove nesting is effective both for interlocking the abutting end-flanges and for cushioning or absorbing shock between them. In this way it contributes significantly to the integrity of the case for protection of the enclosed one or more articles.
There is, however, a limitation with the known form of packaging case on the extent to which the advantage of the mutual ridge-within-groove nesting can be achieved in practice between all flanges. In the case described, the ridges and grooves on the edges of two of the flanges opposite one another are not compatible with achieving nesting between them in that there is ridge-to-ridge alignment between them rather than the ridge-to-groove alignment required for nesting. There is in consequence a gap between those two flanges with the disadvantage that the benefits of interlocking and direct cushioning or absorption of shock between them is not realized.